muscles, blood supply, glands and innervation of the tongue

what are the two groups of muscles each half of the tongue contains?

• intrinsic muscles

• extrinsic muscles

what are the intrinsic muscles of the tongue?

they are according to direction and gives shape to the tongue. they are as follows:

1. superior longitudinal muscle

2. inferior longitudinal muscle

3. transverse muscle

4. vertical muscle

superior longitudinal muscle

• origin: submucosa and fibrous tissue at tongue root

• insertion: apex and edges of tongue

• action: shortens tongues and curls it upwards

• nerve supply: hypoglossal nerve

inferior longitudinal muscle

• origin: root of tongue, near hyoid bone

• insertion: apex of the tongue

• action: shortens tongue and curls it downwards

• nerve supply: hypoglossal nerve

transverse muscle

• origin: median fibrous septum

• insertion: sides of the tongue

• action: narrows the tongue and elongates it

• nerve supply: hypoglossal nerve

vertical muscle

• origin: dorsal surface of the tongue

• insertion: inferior surface of the tongue

• action: flattens the tongue and broadens it

• nerve supply: hypoglossal nerve

what are the extrinsic muscles of the tongue?

they have origins from the mandible bone, hyoid bone and the stylohyoid process. they are as follows:

1. genioglossus muscle

2. hyoglossus muscle

3. styloglossus muscle

4. palatoglossus muscle

genioglossus muscle

a triangular muscle that lies close to (and partly overlaps) its counterpart from the opposite side, located behind the mandibular symphysis / symphysis menti

• origin: superior genial tubercle of the mandible (mental spine of mandible)

• insertion: Fans out and inserts along the entire length of the tongue, reaching from the base to the tip, and also attaches to the body of the hyoid bone

• action: protrudes and depresses the tongue

• nerve supply: hypoglossal nerve

hyoglossus muscle

• origin: body and greater horn of hyoid bone

• insertion: side of the tongue

• action: depresses and retracts tongue

• nerve supply: hypoglossal nerve

styloglossus muscle

• origin: arises from the anterior and lateral surfaces of the styloid process of the temporal bone, near its tip, and from the upper end of the stylomandibular ligament.

• insertion: side of the tongue

• action: elevates and retracts the tongue

• nerve supply: hypoglossal nerve

palatoglossus muscle

• origin: palatine aponeurosis

• insertion: side of the tongue

• action: elevates posterior tongue, and closes the oropharyngeal isthmus

• nerve supply: cranial part of accessory nerves through the pharyngeal plexus

what are the types of glands present in the tongue?

they include serous glands, which open into the trench of the vallate papillae, as well as mucous glands, which open on the inferior surface, especially near the tip of the tongue. both of the types of glands are located between the bundles of muscle fibers

what is the main source of arterial blood of the tongue?

the lingual artery is the main supply. it also receives twigs from the tonsillar and ascending pharyngeal arteries

what is the origin of the lingual artery?

it originates from the anterior surface of the external carotid artery, opposite to the tip of the greater cornu of the hyoid bone

what is the first part of the course of the lingual artery?

the artery forms a loop around the tip of the greater cornu of the hyoid bone. this loop is covered by the hypoglossal nerve.

what is the second part of the course of the lingual artery?

it then runs along the upper border of the hyoid bone, passing deep (behind) the hyoglossus muscle, which separates it from the hypoglossal nerve

what is the third part of the course of the lingual artery?

it is also known as the deep or profunda artery. it ascends on the anterior border of the hyoglossus muscle. it then runs forward on the inferior surface of the tongue, close to the frenulum linguae. at the tip of the tongue, it ends by anastomosing (connecting or joining) with the lingual artery of the opposite side

what are the branches of the lingual artery?

1. suprahyoid artery

2. dorsalis linguae

3. sublingual artery

suprahyoid artery

a small artery that arises from the first part of the course of the lingual artery. it runs along the upper border of the hyoid bone, and is superficial to the hyoglossus muscle

dorsalis linguae

arises from the second part of the course of the lingual artery. it is deep to the hyoglossus muscle and it supplies the posterior part of the tongue

sublingual artery

is a branch from the third part of the course of the lingual artery, and it supplies the sublingual gland.

what are the veins of the tongue?

1. lingual veins (proper)

2. deep lingual veins (vena profunda linguae)

lingual veins

they are two venae comitantes, running alongside the second part of the lingual artery, where they receive the dorsalis linguae veins (draining the posterior tongue)

deep lingual veins

begins at the tip of the tongue. it receives the sublingual vein, which runs along the hypoglossal nerve and forms the vena comitans of the hypoglossal nerve

what do the lingual veins and the vena comitance of the hypoglossal nerve unite to form?

they unite to form a singular lingual vein

where does this single lingual vein terminate?

it either drains directly into the internal jugular vein, or it drains in the common facial vein, which then drains into the internal jugular vein

how does the lymphatic drainage of the anterior 2/3s of the tongue occur?

according to site, differing on whether it is at the tip of the tongue and the frenulum or if it is the margins / sides of the tongue

how does lymphatic drainage occur in the tip of the tongue and the frenulum?

they drain bilaterally into the submental lymph nodes, which then drain into the submandibular nodes, which then drain into the upper nodes cervical nodes

how does lymphatic drainage occur in the margins or sides of the tongue?

they drain into the ipsilateral submandibular nodes, then they drain to the upper deep cervical nodes

how does lymphatic drainage occur in the posterior 1/3 of the tongue?

they drain directly into the deep cervical nodes